UC Santa Cruz

Hematite is a promising material for many different energy conversion and storage applications due to advantages such as low cost, high abundance, and good chemical stability. However, the low electrical conductivity of hematite has hindered the wide application of hematite in for different applications. Atomic doping is one of the most used approaches to tackle the electrical conductivity problem in hematite. Although many works have been done to understand the effects of atomic doping to the electrical conductivity of hematite, there are still many questions not answered yet. In this dissertation, we couple first-principles density functional theory (DFT) calculations with experimental approaches to dive deep into the system and answer unsolved questions in the community by taking advantages of both approaches. We, first of all, employ first-principles DFT calculations to predict how atomic doping impacts the carrier concentrations, carrier mobility and electrical conductivity of hematite. Then we conduct experiments to verify previous predicted results starting from materials synthesis, then materials characterizations, and, in the end, performance measurement. This series of works deepen people’s understanding about how atomic doping impacts the electrical conductivities of hematite and provide a possible validated collaboration mode between first-principles DFT calculations and experimental approaches.